Check if a String is ALL CAPS in PHP

Question

What\'s the best way to see if a string contains all capital letters? I still want the function to return true if the string also contains symbols or numbers.

Answer 1

Check whether strtoupper($str) == $str

To handle non-ascii use:

mb_strtoupper($str, 'utf-8') == $str

Answer 2

This is how I handle ALL CAPS text for my comments section.

if ($str == strtoupper($str))
{
    $str = ucfirst(strtolower($str));
}

Answer 3

If you want numbers included (and by "symbols" most everything else), then what you are actually trying to test for is the absence of lowercase letters:

 $all_upper = !preg_match("/[a-z]/", $string)